Spinners knife

ABSTRACT

An improved blade control thumb knob for a knife with a directly retractable spring-loaded blade that is normally encased within the handle portion, the knife blade having an aperture for engaging yarns, threads, and the like. To effect a severing, the user engages a blade connected projection with his thumb, pushes the blade into operative position, performs the severing operation, and then releases the projection allowing the blade to snap back within the handle.

United States Patent Manning Sept. 23, 1975 SPINNERS KNIFE 497,76512/1950 Belgium 30/335 Inventor: Robert E. g, Cumberland 662,505 2/1965Belgium 30/294 Primary Examiner-Al Lawrence Smith [73] Asslgnee.Brunsw1ck Corporation, Skok1e, Ill. Assistant Examiner j T Zatarga [22]Filed: Oct. 3, 1974 Attorney, Agent, or Firm-.lohn G. Heimovics; David[21] PP NOJ 508,083 S. Guttman; Donald S. Olexa [52] US. Cl. 30/162;30/320; 30/335 57 ABSTRACT [51] Int. Cl. B268 l/08 [58] Field of Search30/162, 320, 335 An improved blade control thumb knob for a knife with adirectly retractable spring-loaded blade that is [56] References Citednormally encased within the handle portion, the knife UNITED STATESPATENTS blade having an aperture for engaging yarns, threads, 851,4824/1907 Barnett 30/320 X and the like- T0 efl a severing the user engagesa 2,474,609 6/1949 w61r 30/162 blade cmmected Prolectlo Wlth hls thumbpushes the 2,607,987 8 1952 Bettenhausen..... 30/162 x blade intoOperative Position, Performs the severing 2,833,032 5/1958 Aciego 30/329x operation, a d t n r l as s th projec ion all ing 3,484,940 12/1969Zell 1. 30/162 the blade to snap back within the handle.

FOREIGN PATENTS OR APPLICATIONS 1 Claim, 7 Drawing Figures. 671,32710/1963 Canada 30/162 Sept. 23.1975 Sheet 1 of 2 3,906,627

' US Patent US Patent Sept. 23,1975 Sheet 2 of 2 3,906,627

FIG. 4

FIG. 6

SPINNERS KNIFE This invention relates to knives used in spinning andrelated industries.

At present knives used in the spinning industry to sever yarns, etc. areof the type having. a standardconfiguration, i.e., the blade ispermanently exposed or of the two position, semi-locking variety wherebythe user pushes a latch to release the blade from an unexposed to anexposed position. The blade, in this instance, locks in the exposedposition necessitating the user again depressing the, latch to retractthe blade.

Safety problems arising with the permanently exposed blade knife areobvious. The two-position retractable blade also presents severe safetyproblems. There is a tendency for the user offthe knife to perform thesevering operation and then put the knife into his pocket withoutretracting the blade. A study of work related accidents in spinningmills reveals that a substantial percentage of these accidents arerelated to workers absentmindedly putting away their knives withoutretracting the blade. An opened blade in a trouser pocket almost alwaysresults in an injury to the worker.

The instant invention is a hand-held knife which has a curved projectionextending outwardly from a slot in the side thereof. The user grasps thehandle and then pushes forward with his thumb to force the projectionalong the slot. This action allows the blade to egress from an openingin the end of the handle. While still holding the projection forwardwith his thumb, the worker performs the severing operation. The blade isonly exposed an amount sufficient to sever the yarn or the like. Aforward portion of the handle cooperates withthe blade aperture todefine a cutting aperture. After the severing operation, the workerlifts his thumb thus allowing an internal spring to snap the projectionand blade back to their initial position. The blade is doubled-endedhaving an aperture in each end and can be reversed. The knife can beused in various other industries which have the same safety problem,e.g., fabric weaving and knitting, fiber production, tire cardmanufacture, extrusion plastics manufacture, electricians, etc.

Accordingly, it is an object of this invention to provide an improvedspinners knife which has little or no injury potential to a user.

It is a further object of this invention to provide a spinning knifewith an automatically retractable blade.

A further object of this invention is to provide a spinners knifeincorporating a hooked cutting blade which can be extended to twoalternate positions and is automatically retractable.

These and other objects will become readily apparent when reference ishad to the accompanying specification and drawings in which:

FIG. 1 is a pictorial view of a user gripping the handle of the knifewith the cutting blade extended.

FIG. 2 is a pictorial view of a user gripping the handle of the knifewith the cutting blade retracted.

FIG. 3 is a plan view of the knife showing one half of the knife inplace and in exploded view.

FIG. 4 is a side view of the blade carrying half of the knife showingthe blade holder.

FIG. 5 is a side view similar to FIG. 4 showing the blade in place.

FIG. 6 is a sectional view taken along lines 66 of FIG. 5 and,

FIG. 7 is apartial 7-7 of FIG. 5. 7

Referring now to FIG. I, the knife is shown designatedgenerally as 10.It has a main handle portion 12 a tapered front 11,,a curved underportion 14 and a hole 13 for a'card; or the like. The handle portionisshaped so as to be easily gripped by a hand H. The users thumb T,engages a curved surface 21 on a slidable projection 20. A screw 42holds the two halves of the knife together. Shown extending outwardlyfrom the front end 11 is curved portion 58 and cutting aperture 56 ofblade 50. In FIG. 1' the blade is forward in one of its two severingpositions while in FIG. 2 the user has released projection 20 and it hasslid rearwardly retracting blade FIG. 3 shows a top view, partiallyexploded, of knife 10. Projection 20 rides in a slot 18 and has anarrowed depending portion 23 which rides in anarrower slot 19 (see FIG.4). As seen in FIG. 4 the curved surface 21 tapers concavely from aheight approximately equal to the axial length of depending portion 23to a height slightly less than one-half the depending portions height.

One half of the knife has been removed in FIG. 4 (the half shown inphantom in FIG. 3) to show the interior details of the knife. As shown,the interior of the knife is hollowed out as at 24. An internallythreaded portion 35 (FIG. 6) extends out from the far wall and isadapted to receive the end of screw 42. The handle has upper groove 30and lower groove 31. Adapted to longitudinally slide in these grooves isblade holder 28. Holder 28 has top flange portion 25 which extendsrearwardly and is secured to depending portion 23 by welding or thelike. A punched-out area 26 provides a tab 27 (seen also in FIGS. 3 and6). The bottom of the blade holder 28 has another flange 29 adapted toslide along groove 31. A portion of blade holder 28 is punched out at 38to provide a tab 39 for engagement by tension spring S. The other end ofspring S is attached to projection 41 and acts to bias the blade holderrearwardly.

FIG. 5 shows the blade 50 in place in holder 28. The blade has mirroredcutting apertures 54, 55. A pair of cut-out portions 51, 52 are providedat the top of the ,sectional view. taken along lines 'blade and areadapted to selectively receive projection 27 therein. The blade is shownwith portion 51 receiving tab 27 thus only partially exposing the curvedportion 56. If tab 27 were to be :seated in portion 52 the forward edgeof blade 50 would be more exposed and cutting aperture 54 would becompletely exposed when projection 20 is thrust forward. Note thephantom position of blade 50 in FIG. 4.

The blade 50 is held in place by the holder 28 and ribbed portions suchas 33 and] 36. FIG. 6 shows the interior detail thereof with cooperatingrib portions 34, 35 and 33, 36. A vertical rib 37 is located within thehandle and is cut away as at 40. A projection 41 therein receives theend of spring S.

The biasing arrangement of the blade allows it to au- 7 tomaticallyretract as soon as the user releases the projection 20 or changes theposition of his hand. The blade holder is tensioned at approximately itsmidpoint vertically so as to evenly pull the holder and blade rearwardlywithout any binding in grooves 30 and 31. The blade, when not in use, isalways within the handle portion so to obviate chances of injury toauser. The dle for biasing the holder in its retracted position; endpoints of the apertures, note 55 in FIG. 5. are an improved bladecontrol thumb knob attached to the slightly spaced from the lower groove31 so not to bl d h ld comprising; :1. an axial beam having a T" shapedcross section While only one embodiment of the device has been 5 andfrom and rear ends the beams top cone. shown and described it should beobvious to those of ordinary skill in the art that many changes andmodifications can be made without departing from the scope of theappended claims.

I claim: l0 1. In a safety knife having 1; a hollow handle;

spending to the top of the the beams depending height corresponding tothe length of the vertical portion of the T"; and

b. an L shaped thumb rest portion integral with the beam and projectingupward from the beams top, the extent of the thumbrests projectiontapering 2 a guiding Channel f d in the handle; concavely from a heightat the beam s from end ap- 3. a blade holder securing a knife blade, theholder p 9 y equal to the beam-,5 axial length to 11 being mounted tolide i th h l between an 15 height at the beams rear end slightly lessthan oneextended position and a retracted position; and half the beamsdepending height. 4. a spring attached between the holder and the han-

1. In a safety knife having
 1. a hollow handle;
 2. a guiding channelformed in the handle;
 3. a blade holder securing a knife blade, theholder being mounted to slide in the channel between an extendedposition and a retracted position; and
 4. a spring attached between theholder and the handle for biasing the holder in its retracted position;an improved blade control thumb knob attached to the blade holder,comprising: a. an axial beam having a ''''T'''' shaped cross section andfront and rear ends, the beam''s top corresponding to the top of the''''T'''', the beam''s depending height corresponding to the length ofthe vertical portion of the ''''T''''; and b. an ''''L'''' shaped thumbrest portion integral with the beam and projecting upward from thebeam''s top, the extent of the thumbrest''s projection taperingconcavely from a height at the beam''s front end approximately equal tothe beam''s axial length to a height at the beam''s rear end slightlyless than one-half the beam''s depending height.
 2. a guiding channelformed in the handle;
 3. a blade holder securing a knife blade, theholder being mounted to slide in the channel between an extendedposition and a retracted position; and
 4. a spring attached between theholder and the handle for biasing the holder in its retracted position;an improved blade control thumb knob attached to the blade holder,comprising: a. an axial beam having a ''''T'''' shaped cross section andfront and rear ends, the beam''s top corresponding to the top of the''''T'''', the beam''s depending height corresponding to the length ofthe vertical portion of the ''''T''''; and b. an ''''L'''' shaped thumbrest portion integral with the beam and projecting upward from thebeam''s top, the extent of the thumbrest''s projection taperingconcavely from a height at the beam''s front end approximately equal tothe beam''s axial length to a height at the beam''s rear end slightlyless than one-half the beam''s depending height.